Side A: Prehistoric Circular Earthworks. Established as the county seat of Pickaway County in 1810, Circleville derives its name from the circular portion of a large Hopewell-era earthwork upon which it was built. The Circleville earthworks, described in 1772 by Rev. David Jones for a Boston magazine, comprised an 1,100 foot diameter circle connected to a 900 foot square. Town director Daniel Dreisbach platted the town directly atop the earthworks, integrating the town plan into the prehistoric landscape. An octagonal courthouse stood directly in the center. Side B: The Squaring of Circleville. By the mid-1830s dissatisfaction arose with Circleville's unique radial-concentric street layout. The Circleville Squaring Company, authorized by the State Assembly in 1837, undertook to convert the "peculiar" town plan into a conventional grid, and by 1856 had completed this work in several phases. Circleville occupies a unique place in the history of American town planning: not only as a subsequent development of Native American engineering, but also as the earliest known example of urban redevelopment in the United States.